MAX16816 Datasheet, PDF (13/33 Pages) Maxim Integrated Products – Programmable Switch-Mode LED Driver with Analog-Controlled PWM Dimming

Programmable Switch-Mode LED Driver
with Analog-Controlled PWM Dimming
Pin Description (continued)
PIN
NAME
FUNCTION
21
SNS- ^{Negative Peak Current-Sense Input. Connect SNS- to the negative side of the switch current-sense resistor,}
R_SENSE.
22
QGND Analog Ground. Ensure a low-impedance connection between QGND and AGND.
23
DGT
Dimming Gate-Driver Output. Connect DGT to the gate of an external n-channel MOSFET for dimming. DGT
is powered by the internal regulator, CLAMP, and is referenced to LO.
Low-Voltage Input. LO is the return point for the LED current. When using the MAX16816 in a buck-boost
25
LO
configuration, connect LO to V_CC. When using the device in a boost configuration only, connect LO to
AGND. Connect LO to the junction of the inductor and LED current-sense resistor, R_CS, when using a buck
configuration.
26
CS+
Noninverting Current-Sense Amplifier Input. Connect CS+ to the positive side of an external sense resistor,
R_CS, connected in series with the load (LEDs).
27
CS-
Inverting Current-Sense Amplifier Input. Connect CS- to the negative side of an external sense resistor, R_CS,
connected in series with the load (LEDs).
Internal CLAMP Regulator Bypass. CLAMP supplies an 8V (typ) output when V_HI ≥ 9V. If V_HI is lower than
9V, V_CLMP is one diode drop below V_HI. The CLAMP regulator powers the current-sense amplifier and
28
CLMP provides the high reference for the dimming driver. V_CLMP must be at least 2.5V higher than V_LO to enable
the current-sense amplifier and dimming MOSFET driver. Bypass CLMP to LO with a 0.1µF ceramic
capacitor.
29
HI
High-Voltage Input. HI is referred to LO. HI supplies power to the current-sense amplifier and dimming
MOSFET gate driver through the CLMP regulator.
Internal Regulator Output. REG2 is an internal voltage regulator that generates EEPROM-programmable
30
REG2 (5V to 15V) output and supplies power to internal circuitry. Connect REG2 to DRI to power the switching
MOSFET driver during normal operation. Bypass REG2 to AGND with a 10µF ceramic capacitor.
31
V_CC Supply Voltage Input
FAULT Input/Output. FAULT is a bidirectional high-voltage logic input/output. FAULT multiplexes a 1-Wire
32
FAULT programming interface with a fault indicator. FAULT is internally pulled up to 5V through a 10kΩ resistor and
a 1.8mA (max) current pulldown to ground.
EP
EP
Exposed Pad. Connect EP to AGND. EP also functions as a heatsink to maximize thermal dissipation. Do not
use as the main ground connection.
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